Timepiece

ABSTRACT

Mechanism for correcting the date indicator of a timepiece. A pinion of correction mounted on a stem has a star type front toothing matingly engageable with the star type front toothing of a sliding pinion mounted on the stem. When resistance to rotation of the pinion of correction exceeds a predetermined limit, the front toothing of the sliding pinion disengages the mating toothing of the pinion of correction to prevent damage to the timepiece.

United States Patent [191 Rochat I I Apr. 23, 1974 TIMEPIECE Primary Examiner-George H. Miller, Jr. [75] Inventor' gsz gzg Neuchatel' Attorney, Agent, or Firm-Silverman & Cass [73] Assignee: Ebauches S. A., Neuchatel,

Switzerland 22 Filed: Mar. 8, 1973 ABSTRACT App]. No.: 339,298

Foreign Application Priority Data Field of Search 58/58, 63, 67, 85.5

References Cited UNITED STATES PATENTS 1/1969 Bennett et al. 58/85.5

Mechanism for correcting the date indicator of a timepiece. A pinion of correction mounted on a stem has a star type front toothing matingly engageable with the star type front toothing of a sliding pinion mounted on the stem. When resistance to rotation of the pinion of correction exceeds a predetermined limit, the front toothing of the sliding pinion disengagesthe mating toothing of the pinion of correction to prevent damage to the timepiece.

4 Claims, 2 Drawing Figures PATENTEB APR 2 3 I974 1 TIMEPIECE The object of the present invention is to provide a timepiece comprising an indicating member, especially for indicating dates, and a control mechanism for the indicating member, comprising a control stem carrying a sliding pinion.

The timepiece of the invention is characterized by the fact that the said stem carries, loosely mounted thereon, a pinion adapted for correction of the indicating member, movement of the said pinion of correction being effected by a sliding pinion having a front toothing engageable with a mating front toothing on the pinion of correction, the shape of the front toothings being such that, when resistance to the rotation of the pinion of correction exceeds a limit value, the action of the said toothings one on each other produces, in either direction of rotation of the stern, a disengagement of the sliding pinion from the pinion of correction, the sliding pinion being moved out of engagement against the action of an elastic return device, permitting the sliding pinion to rotate together with the stem, without driving the pinion of correction.

The drawing shows, by way of example, one embodiment of the invention.

FIG. 1 is a fragmentary, partially diagrammatic view of a portion of a watch in which only the elements necessary to the understanding of the invention have been represented, and

FIG. 2 is a diagrammatic sectional view along line II-Il of FIG. 1 in the direction generally shown.

The watch as represented comprises a date indicating member 1 having the shape of a crown provided with an inner toothing 1a with which cooperates, once per 24 hours, a control member 2, diagrammatically represented, driven by the watch movement.

The watch comprises a control mechanism including a stem 3 moveable between three different axial positions. The first, or pushed position, is neutral, the watch being an electric one; this would be a winding position in the case of a mechanical watch. The second position of the stem, which is intermediary, enables manual set ting of the dates on indicating member or crown 1. This intermediary position is shown in the drawing. The third, or pulled position, is the watch setting position.

The stem 3 carries a sliding pinion 4 operated by a rocking lever 5 articulated on the frame of the movement at a point which is not visible in the drawing. The rocking lever 5 has a portion 5a which is engaged in a groove 6 of the sliding pinion 4. A return spring 7 is engaged upon the rocking lever 5. The rocking lever 5 is operated by a trigger-piece 8, articulated at 9 on the frame of the movement, an ending portion 8a of which is engaged in a groove 10 of the stem 3.

When the control stem 3 is in its intermediary axial position represented in the drawing, the sliding pinion 4 meshes, by means ofa front toothing 4a thereof, with a corresponding front toothing 11a, of a pinion of correction 11. The pinion of correction 11 is loosely mounted on the stem 3 and meshes with a front toothing lb of the date indicating member 1. The teeth of the toothings 4a and 11a are of the so-called star type, with planar faces, the angle between these faces being of The cooperation of the toothings 4a and 11a is such that, when the resistance to the rotation of the pinion of correction 11 goes beyond a limit value, for instance in the case where the correction is attempted at the very moment when one or the other of two driving fingers 2a of the control element 2 is meshed with the toothing la, the action of the toothings 4a and 11a one on each other results in a displacement of the sliding pinion 4 towards the left as seen in FIGS. 1 and 2 against the action of the return spring 7. Displacement of sliding pinion 4 results in disengagement or unclicking of the sliding pinion with respect to the pinion of correction. The disengagement is effected regardless of the direction of rotation of the stem 3. Thus, the pinion of correction 11 is not driven and the control mechanism of the indicating member 1 by the gearing of the movement is not damaged, even if one attempts to effect the correction at the moment when this mechanism is operating.

What I claim is:

1. Timepiece comprising, an indicating member, especially of dates, a control mechanism for said indicating member, the control mechanism including a control stem, a sliding pinion carried on said stem, a correction pinionloosely mounted on the stem to enable correction of the indicating member, the correction pinion having a front toothing, the sliding pinion having a front toothing matingly engaged with the correction pinion front toothing, the shape of said mating front toothings being such that when resistance to rotation of the correction pinion exceeds a limit value the action of said toothings one on each other results in disengagement therebetween, in either direction of rotation of the stem, the sliding pinion being moved out of engagement against the action of an elastic return device whereby the disengaged sliding pinion is rotatable together with the stem without driving the correction pinion.

2. Timepiece as claimed in claim 1 in which the teeth of said front toothings are of star type with planar sides, the angle formed by the sides of each tooth being of at least 90.

3. Timepiece as claimed in claim 1 in which the indicating member has a front toothing and the correction pinion meshes with the front toothing of the indicating member.

4. Timepiece as claimed in claim 1 in which the control mechanism comprises, a trigger-piece operated by the stem during axial movement thereof, and a rocking lever'operated by said trigger-piece, said rocking lever operable to change the axial displacement of the sliding pinion, said elastic return device including a spring acting on said rocking lever. 

1. Timepiece comprising, an indicating member, especially of dates, a control mechanism for said indicating member, the control mechanism including a control stem, a sliding pinion carried on said stem, a correction pinion loosely mounted on the stem to enable correction of the indicating member, the correction pinion having a front toothing, the sliding pinion having a front toothing matingly engaged with the correction pinion front toothing, the shape of said mating front toothings being such that when resistance to rotation of the correction pinion exceeds a limit value the action of said toothings one on each other results in disengagement therebetween, in either direction of rotation of the stem, the sliding pinion being moved out of engagement against the action of an elastic return device whereby the disengaged sliding pinion is rotatable together with the stem without driving the correction pinion.
 2. Timepiece as claimed in claim 1 in which the teeth of said front toothings are of star type with planar sides, the angle formed by the sides of each tooth being of at least 90* .
 3. Timepiece as claimed in claim 1 in which the indicating member has a front toothing and the correction pinion meshes with the front toothing of the indicating member.
 4. Timepiece as claimed in claim 1 in which the control mechanism comprises, a trigger-piece operated by the stem during axial movement thereof, and a rocking lever operated by said trigger-piece, said rocking lever operable to change the axial displacement of the sliding pinion, said elastic return device including a spring acting on said rocking lever. 